Socio-demographic differences in the onset and progression of disability in early old age: a longitudinal study.

OBJECTIVES to analyse socio-demographic differences in the onset and progression of disability. DESIGN analysis of a cohort of people aged 55-69 in 1988-9 and in 1994. SUBJECTS a representative sample of 3543 adults. METHODS we measured severity of disability at baseline and follow-up. We analysed variations in incidence and progression of disability by using logistic regression. RESULTS Baseline severity of disability was similar for men and women but varied by age group, social class, educational qualifications and housing tenure. At follow-up, 36% had worse disability, 12% better and 53% the same as at baseline. Increased severity of disability and new incidence of disability were associated with lower socioeconomic status, baseline self-rated health status, age and gender. High initial levels of disability were associated with improvement at follow-up. CONCLUSION disability can be dynamic, although deterioration is more usual than improvement. The reasons for the associations found between disability and socio-economic status are unclear.